Radioacive Neon Bats ?

Sitting in 4th floor roof garden,late summr, innercity neighborhood with dogs barking, neighbors record player, cars passing, view of Chicago skyline aprox 1 mile away.  Old  aircraft beacon sweeps the sky, to  the  rooftop on  normal rotation.  In the  beacon 2 dull silver disks about the size of  garbage can lids  sweep past aprox. 4 feet from us with accomping  swishhhhhh  noise.  WE turn to watch....mid point of  roof they take off   FAST!~~~ higher faster sound... neighbohood now  dead  quiet..no trafic,  music dogs.  GAin altidute atincreadable speed moving n/nw,  the   lights  begin...yellow/orange, green/blue carnaval ride type  colors.  They intertwine manuveing  as  they  climb. At apex they join together and disapear.  Neighborhood noise  continues, can hear   cars   strating  on main street,  music begins  mid  song on  record player.
All this takes place in the time it takes to say..."what was  that?"  "Radioactive neon bats."  Without saying  another word we returned the  apartment we both wrote a discription of the experience. Without consulting each other the doscriptions matched.
Date is approximate.  PD